dmajor pointed out that there are known miscompilation issues with clang-6 that we've [patched for our version](https://hg.mozilla.org/mozilla-central/log/5f1704e88fa79ad4156497de208c87c58a228ca2/build/build-clang/clang-6-linux64.json) that we use in automation. I'm not sure there's much to do here but maybe add a check for clang-6.0.0 and refuse to build?
dmajor pointed out that there are known miscompilation issues with clang-6 that we've [patched for our version](https:/ /hg.mozilla. org/mozilla- central/ log/5f1704e88fa 79ad4156497de20 8c87c58a228ca2/ build/build- clang/clang- 6-linux64. json) that we use in automation. I'm not sure there's much to do here but maybe add a check for clang-6.0.0 and refuse to build?